Planetary roller leveler for sheet metals

ABSTRACT

Two backup rolls having work rollers arranged on the peripheral surface thereof and adapted to roll thereon are arranged adjacently one above the other. The ends of said work rollers on each said backup roll are supported by a pair of holding disks, and a certain relative speed of rotation is given to said pair of holding disks and the backup roll so that the work rollers simultaneously rotate about their own axis and about the axis of the backup roll. The machine operates as a leveler which levels metal sheet passing between the rotating work rollers.

References Cited UNITED STATES PATENTS Inventor Choichiro Soda Tokyo,Japan 843,305

[21] Appl. No.

Filed 2,565,780 8/1951 [221 3,208,259 9/1965 Maier.........,. F3,210,981 l0/l965 Sendzimir.................... (73] Ass1gnee Agency oflndustnalscience 8: Technology 3 360 973 ["968 Comer Tokyohpan PrimaryExaminerMilton S. Mehr Altorneyl(urt Kelman July 24, 1968 Japan 43/52290ABSTRACT: Two backup rolls having work rollers arranged on theperipheral surface thereof and adapted to roll thereon are arrangedadjacently one above the other. The ends of said work rollers on eachsaid backup roll are supported by a pair zclumsnnrawmg of holding disks,and a certain relative speed of rotation is [52] US. given to said pairof holding disks and the backup roll so that 32 Priority [54] PLANETARYnoun-3n LEVELER FOR SHEET METALS the work rollers simultaneously rotateabout their own axis Int. and about the axis ofthe backup roll. Themachine operates as [50] Field of a leveler which levels metal sheetpassing between the rotating work rollers.

Patented Aug. 10, 1971 PRIOR ART INVENTOR c: Hora R0 50 0A Patented Aug.10, 1971 3 Shegts-Sheet 2 8 no 8% .8 8 R 0 n wmw Patented Aug. 10, 19713,591,952

3 Sheets-Sheet 5 v INVENTOR Cl-FOlCtflRO SODA I AGENT PLANETARY ROLLERLEVEL ER FOR SHEET METALS The present invention relates to a planetaryroller leveler for sheet metals.

The known roll levelers for sheet metals comprise linear rows of workrollers arranged in two different horizontal planes, each of saidrollers being connected to a universal joint and adapted to be driven bya motor. When a sheet of metal to be leveled is passed between said rowsof work rollers, it is subject to repeated plastic deformation by therotation of said work rollers and thus made truer in flatness.

When a material small in thickness or high in elasticity is to beflattened by such a roller leveler, the diameter of the work rollersmust be decreased. When this is done, the rollers become less rigid withthe decreasing in diameter. To compensate for this, backup rolls areusually arranged outside of the work rollers.

Since reduction ofthe roller diameter also requiresdimensional reductionof bearings and joints and since special devices for reinforcement mustbe added, levelers for such materials as mentioned above have a certainlimit both in size and accuracy. The rollers of the smallest rollerlevelers now on the market are no less than mm. in diameter. Thus, suchmaterials are difi'icult to level and the accuracy of the leveling ispoor.

Thin and highly flat sheets of material of 0.1 mm. or less in thicknessare presently in demand as a result of the refinement andminiaturization of machines and apparatuses in the electronic and otherindustries. As a tension leveler wherein sheet metal is leveled byrollers while being subject to tension has recently been developed, longstrips of considerably small thicknesses can now be leveled. But it isimpossible to apply such tension method to small materials such aspunched parts so that such sheets of under 0.1 mm. in thickness havehitherto been impossible to level from end to end.

The principal object of the present invention is to provide a levelercapable of leveling sheet metal of under 0.1 mm. in thickness or thinand highly elastic materials with high accura- Another object of thepresent invention is to provide a leveler capable of leveling with easesmall parts made from thin sheet metal which cannot be leveled byconventional levelers. v i

According to the present invention, two backup rolls having work rollersarranged on the peripheral surface thereof and adapted to roll thereonare arranged adjacently one above the other. The ends of said workrollers on each said backup roll are supported by a pair of holdingdisks, and a certain relative speed of rotation is given to said pair ofholding disks and the backup roll so that the work rollerssimultaneously rotate about their own axis and about the axis of thebackup roll. Thus a sheet of metal passing through the gap between theupper and lower rotating work rollers is leveled. This allows themanufacture of a leveler whose work rollers have a diameter of 2 mm.without causing a reduction in the rigidity of the rollers as is thecase with the conventional levelers, so that thin and highly elasticmaterials or thin and small-sized materials may be leveled with highaccuracy. This advantage is attributable to the fact that the workrollers have a great resistance to being bent as they are rolling alongthe highly rigid backup rolls in contact therewith.

When work rollers; of 2 mm. in diameter are used in the leveleraccording to the present invention, the minimum sheet thickness whichcan be leveled is one-half or one-third of that of the conventionallevelers. Spring plates of nickel-silver, phosphor bronze and stainlesssteel of o.l0.08 mm. in thickness for electronic telephone exchanges,magnetic materials of -10 p. in thickness for the memories of electroniccomputers, 20 p. copper plates for printed circuits, 0.08 mm. copperspring plates for diaphragms, etc, none of which could mechanically beleveled, can be leveled easily and highly accurately. This will greatlyease the production of precision apparatuses.

Other objects and features of the present invention will become apparentfrom the following detailed description in reference to the accompanyingdrawing in which:

FIG. 1 is an illustrative view of the principle of a conventionalleveler;

FIG. 2 is an illustrative view showing the relationship of therespective rotations of the work rollers and backup rolls according tothe present invention;

FIG. 3 is a side elevational view of the leveler according to thepresent invention;

FIG. 4 is a front elevational view of the leveler of FIG. 3;

FIG. Sis a plane view taken along the line VV of FIG. 3;

FIG. 6 is an enlarged sectional view through the shaft of the backuproll; and

FIG. 7 is an illustrative view of an embodiment of the driving system ofthe present invention.

In FIG. 1, two groups of work rollers 1 are arranged linearly one aboveanother and each of said work rollers is rotated by an electric motornot shown. A sheet of metal 3 is leveled by being passed between therows of said rotating work rollers. When, for example, a high elasticmaterial is to be leveled, the diameter of the work rollers must belessened. Since the rigidity of the rollers decreases as the diameterthereof decreases, backup rolls 2 are arranged on the outside of thework rollers l to compensate for the loss of rigidity. However, thediameter of the rollers cannot be lessened beyond a certain valuebecause of construction and accuracy considerations, for the backuprolls and joints must be also made small sized if the work rollers aremade thinner.

Referring now to FIG. 2-6, backup rolls 4 and 4' are arranged adjacentlyone above the other on a machine base 6 and supported by theirprojecting shafts 5 and 5 on upper and lower bearing boxes 7 and 7.

The lower backup roll 4' is driven by a speed change gear 40 through-theshaft 5 and an universal joint 41'. The upper backup roll 4 rotates atthe same speed as the lower backup roll 4' with the help of a gear wheel8 secured to the shaft 5, transmission gear wheels 9 and 10 and a gearwheel 11 secured to the shaft 5'.

Pair of holding disks 12, 12' are provided opposed to each other one oneach end of the backup roll 4, 4' and secured to gear wheels 13, 13'rotatably mounted on the shaft 5, 5' through bearings by means of screws30.

Arranged between the opposed holding disks 12, 12' are small-diameterwork rollers 14, 14 adapted to roll on the peripheral surface of thebackup roll 4, 4'.

To ensure that the work rollers 14, 14' revolve their own axis with theaid of the frictional force of the backup roll 4, 4', grooves 15 areprovided on both ends of the work rollers 14, 14' and bands 17' of ofmetal or high-tensile plastics are threaded over the pulleys 16 at theend of arms 20, pulleys 16 at the end of levers 18 and said grooves 15.The tension of the bands 17 can be adjusted by means of springs 19provided at the opposite end of levers 18.

The gear wheels 13, 13"to which the holding disks 12, 12' are securedrotate at the same speed through gear wheels 24 and 25 provided onconnecting plates 21 and 22 which have one end pivotally mounted on theshafts 5, 5'. The connecting plates 21 and 22 are connected by aconnecting plate 23 at one end of which is on the shaft 26 of the gearwheel 24 and at the other end of which is on the shaft 26' of the gearwheel 25. The revolution of the speed change gear 40 is transmittedthrough an intermediate gear wheel 29, a gear wheel 27 rotatably mountedon the shaft 5' and a gear wheel 28 secured to the-shaft 26' in parallelwith the gear wheel 25.

When the upper and lower groups of work rollers 14, 14 are in a positionwherein they butt against each other, it is necessary to locate one workroller of one group in the center between two adjacent rollers of theother group. For this purpose a shaft 31 is provided extending from thetip of one connecting plate 22 to the tip of the other connecting plate22 and one end of threaded shaft 32 having a handle at the middlethereof is screwed into machine base 6 while its other end contacts saidshaft 31 at the middle thereof. The height of said shaft 31 is changedby turning said handle to cause the connecting plates 21 and 22 torotate round the shafts and 5'. respectively. thereby allowing fineadjustment of the position of the work-roller groups relative to eachother.

To adjust the gap between the upper and lower groups of work rollers l4,14' arranged around the upper and lower backup rolls 4, 4' In accordancewith the thickness of the sheet to be leveled. the bearing box 7'supporting the lower backup roll 4' is fixed, while the bearing box 7supporting the upper backup roll 4 can be adjusted in height along aguide on the machine base 6 through a threaded rod 33 extending throughthe machine base 6 and pressing at one end against the top of saidbearing box 7, a worm gear 34 secured to the other end of said rod, awonn 35 engaged with said worm gear and a handle 36 for turning saidworm 35.

A plate 37 for holding the sheet metal to be worked is fixed to themachine base 6.

Referring to FIG. 7, the revolutions of motor 38 are transmitted througha reduction gear 39 to the speed change gear 40, which controls thespeed ratio of the backup rolls 4, 4' and the holding disks 12 to adesired value. Naturally, the motor, reduction gear and speed changegear may be accommodated within the machine base.

When the upper backup roll 4 and holding disks ]2 and the lower backuproll 4 and holding disks [2 are rotated in the same direction as shownby arrows in FIG. 2, the groups of work rollers 14 and 14' revolve abouttheir own axis with the help of friction against the backup rolls 4 and4 and simultaneously about the axis of the backup rolls 4 and 4',respectively. In this case, if there is no slippage between the workrollers and the backup roll, the relationship between the number ofrevolutions of the backup rolls N,, the number of revolutions of theholding disks N and the number of revolutions of the work rollers N, inrpm. is expressed by the following:

wherein D is the diameter of the backup rolls in mm., and

D is the diameter of the work rollers in mm. Further, a sheet of metalinserted between the upper and lower groups of work rollers 14 and 14'which revolve about the axis of the backup rolls while revolving abouttheir own axis is passed at a speed thereby to be leveled by repeatedplastic bending deformation. (when v 0, the sheet moves to the right andvice versa.)

The amount of intermesh of the upper and lower work rollers takes themaximum in the middle range where the two groups of rollers are closelyopposed. Hence, the bending moment applied to the sheet increasesgradually to the maximum as the sheet proceeds and thereafter decreasesgradually until the flatness of the sheet is attained.

The minimum sheet thickness which can be leveled by the presentinvention can be expressed by the following equation in regard to theproof stress 0-,, and longitudinal elastic modulus E of the material andthe diameter of the work rollers D wherein a is a constant dependentupon the tensile force applied to the sheet and normally about 8 withouttension. With no tensile force applied to the sheet. it follows from theabove equation that !=0.04 I) for phosphor bronze for springs of 0,,kg./mm. and 5 12.600. lf D,=2 mm., r-=0.08 mm., while !=0.2 mm. for 0 5mm Further. for stainless steel of #0 kg./mm !=().08 mm. for D,=5 mm.and indeed t=0.03 mm. for D,=2 mm.

Thus, when work rollers of 2 mm. in diameter are used in the leveleraccording to the present invention. the minimum sheet thickness whichcan be leveled can be reduced down to one-half or one-third ofthat ofthe conventional levelers.

Furthermore, it is also possible to use the leveler according to thepresent invention as a so-called tension leveler by applying tension tothe sheet in the longitudinal direction. In this case, in contrast withconventiona levelers, It is possible by varying the speed ratio of thebackup rolls and the holding disks and by thus varying the frequency atwhich the sheet is bent to freely adjust not only the degree of flatnessobtained but also the degree of reduction of sheet thickness.

While there has been described in connection with the preferredembodiment of this invention, it will be obvious to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the invention, and it is aimed, therefore, to cover inthe appended claims all such changes and modifications as fall withinthe true spirit and scope of the invention.

What I claim is:

l. A planetary roller leveler for sheet metals comprising;

a machine base,

a pair of backup rolls arranged adjacently one above the other andhaving work rollers arranged on the peripheral surface thereof, saidwork rollers being adapted to roll or the peripheral surface of saidbackup rolls,

holding disks for holding said work rollers at both ends thereof, saiddisks being rotatably mounted on the shafts of said backup rolls.

means for pressing said work rollers against said backup rolls, meansfor centering one work roller of one of the upper and lower groups ofwork rollers between two adjacent rollers of the other group,

means for adjusting the gap between the upper and lower groups of workrollers,

means for rotating said pair of backup rolls, and

means for rotating said holding disks, whereby said backup rolls andholding disks are rotated relative to each other for causing said workrollers simultaneously to revolve about their own axis and the axis ofsaid backup rolls; wherein a sheet of metal to be leveled is allowed topass between the upper and lower groups of said rotating work rollers.

2. The leveler as set forth in claim 1, wherein said means for pressingsaid work rollers against said backup rolls comprises high tensile bandsthreaded on grooves provided on both ends ofsaid work rollers andpulleys attached to said machine base.

1. A planetary roller leveler for sheet metals comprising; a machinebase, a pair of backup rolls arranged adjacently one above the other andhaving work rollers arranged on the peripheral surface thereof, saidwork rollers being adapted to roll on the peripheral surface of saidbackup rolls, holding disks for holding said work rollers at both endsthereof, said disks being rotatably mounted on the shafts of said backuprolls, means for pressing said work rollers against said backup rolls,means for centering one work roller of one of the upper and lower groupsof work rollers between two adjacent rollers of the other group, meansfor adjusting the gap between the upper and lower groups of workrollers, means for rotating said pair of backup rolls, and means forrotating said holding disks, whereby said backup rolls and holding disksare rotated relative to each other for causing said work rollerssimultaneously to revolve about their own axis and the axis of saidbackup rolls; wherein a sheet of metal to be leveled is allowed to passbetween the upper and lower groups of said rotating work rollers.
 2. Theleveler as set forth in claim 1, wherein said means for pressing saidwork rollers against said backup rolls comprises higH tensile bandsthreaded on grooves provided on both ends of said work rollers andpulleys attached to said machine base.